A strut is a structural device arranged between two or more elements that provides structural support therebetween. A strut may include components for vibration damping, and thus be capable of providing vibration-damped structural support between two or more elements. Vibration damping struts may be employed in a vehicle system to provide tension in a serpentine belt assembly for an internal combustion engine, or as a suspension component.
Known vibration damping strut configurations include a moveable piston within a cylinder that span between first and second attaching points to provide vibration-damped structural support. The piston and cylinder form a fluidic chamber that fluidly connects to a reservoir via a normally closed or closed-biased check valve. Normally closed check valves are arranged to prevent flow of fluid from the pressure chamber into the reservoir, such as in response to conditions when the first and second attaching points are moving towards each other. Normally closed check valves are further arranged to permit free flow of fluid from the reservoir into the pressure chamber, such as in response to conditions when the first and second attaching points are moving away from each other. Such strut configurations rely on suction to open the check valve and gravity/pressure to close the check valve. By relying on suction, some strut movement may not lower the chamber pressure sufficiently to open the check valve under some operating conditions when a normally closed check valve is employed. Furthermore, an objectionable audible sound, e.g., a rattle may be generated when movement between the first and second attaching points causes the pressure in the fluidic chamber to dither and drop to pressure levels low enough to create suction and open a normally closed check valve, which can also aerate the fluid when pressures drop below the saturation pressure of the fluid.